Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipments. The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. These smaller electronic components also require smaller packages that utilize less area than packages of the past, in some applications.
One type of smaller package for semiconductor devices that has been developed is the wafer level package (WLP). A wafer-level package of integrated circuits (ICs) made of heterogeneous technologies, which may be referred as a heterogeneous integration, reduces manufacturing cost, while providing high performance and high density. Initial applications of heterogeneous integration, also referred to as hyper-integration, have been on microprocessors, application specific integrated circuits (ASICs), and memories. Other applications of heterogeneous integration are being explored for radio frequency (RF), analog, optical, and micro-electro-mechanical systems (MEMS), where integration of ICs made with heterogeneous technologies, such as digital CMOS, SiGe RF BiCMOS, any existing or future technologies can be wafer-level “packaged.”
Many existing WLP techniques for heterogeneous integration technologies are based on vertically stacking the ICs. Such techniques may require a larger height which may not be available in certain situations. Therefore there is a need to develop other forms of WLP techniques for heterogeneous integration technologies.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale.